Electric clock system.



H. 0. HARRISON.

ELECTRIC CLOCK SYSTEM.

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H. O. HARRISON.

ELECTRIC CLOCK SYSTEM.

APPLICATION FILED MAR. 16, 1909.

Patented Dec. '21, 1909.

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H. O. HARRISON.

ELECTRIC CLOCK SYSTEM.

APPLICATION PILLD MAR.16, 1909.

Patented Dec. 21, 1909.

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UNITED s'rA'rns rnrENr OFFICE.

HARRY OLIVER HARRISON, OF WIGHITA, KANSAS, ASS IGNOB. OF ONE-HALF TDSAMUEL McCBEAB'Y, F WICHITA, KANSAS.

ELECTRIC CLOCK SYSTEM.

Specification of Letters Patent.

' I Application filed March 16, 1909. SerialNo. 483,786.

7 following is a specification.

This invention has reference to improvements in electric clocksy'stemswherein a master clock causes the periodic sending to line of electricalimpulses which in turn actuate the local clocks all at the same time andto the same extent.

It is the object of the present invention to provide a clock system ofsuch character wherein the electrical impulses sent to line shall be ofthe shortest possible duration and shall be maintained upon the lineonly long enough to cause the actuation of the clocks,

the duration of the impulses being very short as compared with the timeperlod between said impulses.

In accordance with the present invention the master clock includes aclock movement of any capacity, whether one, eight, thirty, or more dayscontinuous running at one winding or whether it be an electric clockmovement or any other suitable clock movement which will answer thepurposes of a master cloc The master clock has applied thereto anattachment whereby at stated intervals electric impulses are sent toline and are maintained for the shortest possible time to becomeeffective at the local clocks so that the drain upon the current sourceis reduced to the minimum.

At the local stations the time indicating movements are of extremelysimple character and are given impulses at stated time in,- tervalsbythe electric impulses produced upon the line by the master clock.' Thetime indicating hands at the local clocks are not continuously movinghands asin the ordinary clock movement'but move step by step.

at predetermined intervals, say at intervals of one minute but otherwisesynchronize in movement with the master clock so that the time kept bythe master clock is re roducedsimultaneously in all the local cloc swhich latter may be of any suitable number and as widely distributed asmay be desired within the range of the efiective action of theelectrical source. g

The invention will be best understood from a. consideration of thefollowing detail description taken in connection with the accompanyingdrawings, forming a part of this specification in which drawings,

Figure 1 is a structural diagram of the master clockand the meanscoacting there- 'with for sending momentary electrical impulses to line.Fig. 2 is an end elevation of one of the local clock movements. Fig. 3is a side elevation of the same with parts broken away, and in section.Fig. 4 is a detail view of the armature and its mounting as found in alocal clock. Fig. 5 is a detail view of a portion of the sendingmechanism for producing the electrical impulses on the line, the view ofFig. 5 being at right angles to that of Fig. 1. Fig. 6 is a diagramPatented Dec. 21, 1909.

showing illustratively the master clock and a number of local clockscontrolled thereby.

Considering first the master clock as illustrated in-Fig. 1 and alsohaving some parts illustrated in Figs. 5 and 6, there is shown asuitable frame 1 in which is mounted a spring 2'which may be takenillustrative of vany source of power capable of operating for anydesired time period and may be capable of driving the master clock forone day, or eight days, or thirty days, or for a more extended period.

' The power of the spring. is transmitted by gear wheels3, 4, 5, 6 tothe escapement mechanism 7 Let it beassumed that the gear wheel 6 makesone complete rotation within a comparatively short time period say onein fifteen seconds, or one in thirty seconds, or even one in sixtyseconds depending upon the general arrangement of the clock train. Uponthe arbor 8 of this wheel 6 there is secured a disk 9'f1'om which .12-vprojecting between and controlled by the pins 10 and this arm 12carries at its free end a laterally projecting roller 13 fora purposewhich will presently appear. Each time'th'e arbor 8 is caused to'movethrough one complete rotation one of the pins 10 will engage the arm 12and lift the same from a pendent position to a position where the armpoints toward the zenith and when carried beyond this last namedposition the arm becomes overbalanced and falls by gravity about thearbor 8 as an axis until it engages the other pin 10 and its movement isthereby arrested, the arm being slowly lowered to thependent positionby. the progressive movement of the pin 10 which arrested thegravitating movement of said arm. It will be understood, of course, thatthe mounting of the pin disk 9 and arm 12 on the arbor 8 is to be takenas illustrative only, and when it is desirable that the movement of thearm 12 should take place at other intervals than would be the case whencarried by the arbor 8, then the arm 12 and pin disk 9 are mounted onanother arbor suitably geared, at the proper place, to the clock train.Of course the gearing of the local clocks, hereinafter described, will,in such case, be appropriately modified to act under the changed timeperiods of the actuating impulses. I

Mounted on some fixed support such as the casing inclosing the, masterclock movement, which casing however is not shown in the drawings, thereis a bracket 1 1- having at one end a post or standard 15. Mounted onthe bracket 14: is a vessel or container 16 of iron or glass'and thiscontainer holds a quantity of mercury indicated at 17. If the containerbe of iron a conductor 18 may be directly connected therewith, or if thecontainer be of glass then the conductor 18 must be introduced into thecontainer so as to be brought into electric contact with the mercurytherein'for a purpose which will presently appear.

Fast tothe post 15 is aninsulating strip 19 and secured to thisinsulating strip is a conducting strip 20 bent to horizontal positionand preferably made of some spring material so as to be both elastic andelectrically conducting. The free end of the strip 20 is'carried to aposition to be in the path of the roller on the arm 12 as it gravitatesfrom the zenith position toward the pendent position andthe relationbetween the strip 20 and the roller on the arm 12 is such that duringthis movement of the arm 12 from the zenith toward the pendent position,the strip 20 will be engaged by the roller 13 and the said strip will bebent downward and before the arm 12 is arrested by the lower pin 10 thestrip 20 will escape from the engagement with the roller 13 and becauseof its elastic tendency will snap back toward the normal horizontalposition, rebound beyond this position being prevented by a suitablestop 21 in the path of said strip.

The strip carries a finger 22 extending downward into the vessel 16 to aposition where its free end is above the mercury but so related theretothat when the strip 20 is bent downward by the engagement of the roller.19 with its free end the end ofthe finger 22 will be caused to dip intothe merelectrical reasons it is not advisable to make' the finger 22 ofiron, the free end of the finger may be tipped with iron as indicated at23 so as to be unaffected by the mercury, but the short iron extensionwill not offer sufficient electrical resistance to be considered.

The spring strip 20 is connected to one end of a conductor 24 leading toa battery 25 or other suitable source of electric current and from thebattery there leads another conductor 26 which together with theconductor 18 may be carried to any distant point or points desired,these two conductors constituting the line conductors. Assuming thatthemaster clock shown in Fig. 1 is continuously running and is keepingpro er time, which may be indicated by suita le hands and dial not shownin the drawing: then at stated periods the arm 12 will brought to thezenith position and will then be overbalanced and fall rapidly bygravity until the roller 13 engages the spring member 20 and bends thesame sufficiently to cause the end 23 of the finger 22 to dip in themercury 17, after which the roller 13 escapes from engagement with thespring strip 20 and is ultimately arrested by engagement with the pin 10then constituting the lower pin.

When the finger 22 dips into the mercury 17 then there is established acircuit which may be traced as follows: Starting from the battery 25 thecircuit is established through the conductor 24 to the strip 20, thencey way of the finger 22 and its terminal 23 to the mercury 17, thence bythe conductor 18 to the distant point of utilization of the current andthe circuit is completed through the conductor 26 back to the battery25. This circuit is established every time the wheel 6 with its arbor 8makes one rotation and while it may take a considerable time for thiswheel to make one complete rotation, the circuit over the line wires isclosed but a' very small fraction of this time, the circuit remainingclosed but a fraction of a second, while the impulses are given at timeintervals of many seconds or even, in some casa at time intervals of aminute.

The local time pieces are best shown in Figs. 2 and 3. There is provideda suitable frame composed of end plates 27 joined at appropriate pointsby bolts 28 passing through s acing sleeves 29, or the bolts may bereduced at the ends where passing through the plateso27 as is customaryin clock movements. The frame 27 carries an arbor 30 upon which ismounted the usual minute hand 31 and from this arbor is driven the 34,this being the customary arrangement in ordinary clock movements; On thearbor 30 between the plates 27 is secured a toothed wheel 35, and sincethe arbor will be used in the usual manner for setting the hands 31 and34 by means of a suitable knob 36 the wheel 35 is frictionally mountedon the arbor 30 after the customary manner of mounting the driving wheelupon the hand arborof a clock.

The teeth of the wheel 35 are indicated at 37 and it will benoted thattheseteeth are provided with terminal-ends all slanting one way. Thiswheel 35 is the drive wheel for the arbor 30 and it is actuated by theelectric impulses coming overthe line wires 18and 26 on the closures ofthe'main circuit by the master clock.

Mounted on one of the sleeves 29 is a pendent arm 38 having an angleextension 39 carrying one end of a pawl 40 by means of a pivot 41.Thepawl 40 carries a tooth 42 arran ed to engage the teeth 37 to propelthe whee 35 in one direction while the tooth 42 will ride idly overthese teeth when the pawl moves in the opposite direction. i stop member43 is carried by one of the plates 27 in the pathof the free end of thepawl 40 so that its movement in one direction beyond a certainpredetermined limit may be prevented, but the arrangement of this stopplate is such that when the pawl is moved in the reverse or idledirection the rising of the pawl to permit the tooth 40 to pass over theteeth is not interfered with.

The base plate of the clock movement at the local station is indicatedat 44 and this may be extended to one side and there be formed into orcarry a post 45 to which is secured an electromagnet 46 of the horseshoetype by preference. Vithin operati-ve'relation to the polar ends of themagnet 46 is an armature 47 mounted on an armature lever 48 pivotallysupported on one of the bolts 28, this lever being fast on one of thesleeves 2S) so as lto turn upon the bolt and at' the same time space theplates 27 at this point. A spring 49 fast at one end to the clockmovement frame and at the other end to the lever 48 tends constantly t6move the armature 47 away from the magnet. A stop member '50 projectingfrom one frame member 27 is carried into the path of the armature leverto limit its movement away from the magnet so that the armature isalways maintained within active relation of the polar ends of themagnet.

The free end of the armature lever 48 is connected to the pendent arm 38by a link 51 and this link may have at each end oppositely threadedportions arranged to screw into threaded sockets on yokes 52 pivotallyconnected to the armature lever 48 and the l l l arm 38 respectively. Bythis means the relative positions of the armature lever and the arm 38with the pawl 40 carried thereby may be readily adjusted.

Pivoted to one of the frame members 27 is a backstop pawl 53 having atooth 54 adapted to engage the teeth 37 of the wheel 35. This pawl 53 ismaintained with its tooth 54 in normal engagement withthe teeth 37 by asuitable spring 55.

When an impulse comes over the line then the magnets 46 are energizedand attract the armature 47. This causes the arm 38 of each local timepiece to swing about its pivotal support under the pull of the link 51and the tooth 42 of the pawl 40 being in normal engagement with theteeth 37 engages one of the latter in a manner to cause a rotativemovement of the wheel 35. On the forward movement of the wheel 35 thetooth'54 of the pawl 53 is inactive and simply rides idly over theteeth. The parts are normally so adjusted that-the pull of the magnetupon the armature 47 will move the armature lever 48 a distance whichwill cause the swing of the arm 38 sufficiently to move the wheel adistance of one tooth so that when the armature lever is returned to itsnormal position by the spring 49 after the magnet has become deenergizedthe tooth 42 will move back over a tooth and engage behind the nexttooth in order to that which it first actively engaged and the tooth 54of the pawl 53 will drop behind a tooth 37 to prevent a reverse movementof the wheel 35 on the return movement of the pawl 40 to its normalposition on the deenergization of the magnet 46. Thus at each impulsesent over the line the wheel 35 is rotated a distance equal to thedistance between two teeth and this ordinarily will agree to thedistance between the minute indications on the clock dial so thatordinarily the minute hand will be advanced step by step at minuteintervals and the hour hand of course will move correspondingly. If itbe found advisable to move the clock hands at longer or shorterintervals than the minute intervals then the master clock will beconstructed accordingly to send impulses at longer or shorter intervalsas desired.

. Let it be supposed that a systemis installed with a master clock andas many 10- cal clock movements as may be desired. In this system themaster clock controls and furnishes the power for actuating all the 10-20 will immediately move back to its norma position against the stop 21,the latter preventing any material vibration of the said strip 20. Thedownward movement of the strip 20 has caused the dipping of the end 23of the finger 22 into the mercury 17. Of course it will-be understoodthat mercury is not the only conducting medium that may be usedbut someconducting solution may be.

employed in place of the mercury, in which case the end 23 of the finger22 will be composed of a suitable conducting material inert to anychemical action on the part of the solution. Because of the normallynon-corrosive properties of platinum and its suflicient conductivity forthe purpose the finger 22 may be made of such material if desired. Thetime period of immersion of the end 23 of the finger 22 in theconducting medium 17 is but a small fraction of a second, but this issufficient to complete the electric circuit long enough to cause animpulse to traverse the several magnets 46 of the local clock movementsand to cause the energization of these magnets and the attraction oftheir armatures 47 and the turning of the wheels 35 by such movements ofthe armatures The electrical impulses cease almost instantly andconsequently the drain on the battery 25 or other source of electricenergy is reduced to a minimum. The parts may be so adjusted that thereis practically no waste of electric energy and the battery is closed onthe circuit only long enough and no longer than is necessary to causethe proper energization of the ma ets 46.

It is evident that the local clocks may be connected up to the linecircuits either in series or in multiple are as may be-found desirable.Furthermore. it is immaterial whether the sending of the impulses toline he in rapid or slow succession, for the time limitof each impulsewill be the same.

What is claimed is 1. In an electric clock system, a master clock, anelastic switch arm, a contact member carried by the switch arm andadapted to close an electric circuit, a pivoted arm movable into directengagement with the free end of the elastic'switch arm and past the sameby gravity, and means in the master clock for rotating the pivoted armand periodically releasing the same to the action of gravity-to causethe momentary active movement of the switch arm.

2. In an electric clock system, a master clock, an elasticswitch armhaving a normal tendency to the inactive position, a contact membercarried by the switch arm, a merrcury cup entered by saidcontact memberin a normal position out of contact with the mercury; a pivoted gravityarm movable into direct engagementwith the free end of the elasticswitch arm and past the same by the action of. gravity, and means in themaster clock for rotating the pivoted arm and periodically releasing thesame to the action of gravity to cause the momentary active movementofthe switch arm.

3. In-an electricclock system, a master clock, an electric circuitcontrolled thereby, and local clocks controlled by impulses sent oversaid electric circuit, each local clock comprising an electro-magnet, anarmature lever actuated thereby, a ratchet wheel, a clock-hand carryingarbor actuated by said ratchet wheel, a pawl for moving said ratchetwheel actively, means for engaging said pawl and preventing the movementof the ratchet wheel beyond the point to which it was actuated by thepawl, 21 pivoted hanger carrying the pawl and adjustable connectionsbetween the armature lever and the hanger carrying the pawl.

In testimony that I claim the foregoing as my own, I have hereto aflixedmy signature in the presence of two witnesses.

HARRY OLIVER HARRISON.

Witnesses:

WM.- G. HERSHBERGER, C. B. CLEAVELAND.

